package com.doit.demo.day02.transformations;

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.common.typeinfo.TypeHint;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.operators.StreamFlatMap;
import org.apache.flink.util.Collector;

/**
 * @DATE 2022/2/27/11:00
 * @Author MDK
 * @Version 2021.2.2
 *
 *   FlatMap的底层实现
 **/
public class FlatMapDemo2 {
    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        DataStreamSource<String> lines = env.socketTextStream("linux01", 8888);

        FlatMapFunction<String, Tuple2<String, Integer>> flatMapFunction = new FlatMapFunction<String, Tuple2<String, Integer>>() {
            @Override
            public void flatMap(String value, Collector<Tuple2<String, Integer>> out) throws Exception {
                String[] words = value.split(" ");
                for (String word : words) {
                    out.collect(Tuple2.of(word, 1));
                }
            }
        };

        SingleOutputStreamOperator<Tuple2<String, Integer>> wordAndOne = lines.transform(
                "MyFlatMap",
                TypeInformation.of(new TypeHint<Tuple2<String, Integer>>() {}),
                new StreamFlatMap<>(flatMapFunction));

        wordAndOne.print();

        env.execute();
    }
}
